Abstract: Abstract:There was serious scale formation in the inlet baffle of the induced draft fan of a domestic biomass fuelfired power plant, which caused the baffle opening can not be adjusted normally. So it is impossible to adjust the boiler load, and the unit can not operate safely and stably. The Xray spectrum analysis test and the Xray diffraction analysis test for the deposition were carried out, and the test results show that the deposition is NH4Cl crystalline with high purity. The components of the biomass fuel and the soil were analyzed, and the results show that the NH4Cl is mainly from the soil carried with the biomass fuel. The formation condition of the NH4Cl crystalline was discussed, and it was verified that the main factor causing scaling on the baffle is too low flue gas environmental temperature near the baffle. A hot secondary air flow was led into the inlet baffle of the induced draft fan, the flue gas environmental temperature was raised, and the scaling on the baffle was lightened. The baffle opening can be adjusted normally.

Key words: Keywords:biomass fuelfired power plant, induced draft fan, baffle, scale formation, ammonium chloride